L4705 STMICROELECTRONICS | Alldatasheet
Document overview
- Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
- PDF pages: 3
Technical content
i2- S (e) PRELIMINARY DATA + G1S- O30 ‘ VERY LOW DROP VOLTAGE REGULATORS @ INPUT/OUTPUT DROP TYP. 0.6V L4700 series regulators are specially designed @ 500mA OUTPUT CURRENT for automotive and industrial applications where the electrical environment is very demanding and @ 80V LOAD DUMP PROTECTION low voltage drop is required. For example, the @ -80V TRANSIENT PROTECTION L4705 can be used in 5V automotive applica- tions, continuing to function even when the @ REVERSE POLARITY PROTECTION battery voltage falls to 6V, a common event . @ OVERVOLTAGE PROTECTION during starting. Moreover, the L4705 is fully pro- @ OUTPUT CURRENT LIMITING tected against the transients, overvoltages and polarity reversal encountered on the battery rail. . @ THERMAL SHUTDOWN L4700 series voltage regulators feature a very low Val oN voltage drop, an output current of 500mA and —< T0-220 protection against load dump transients of + BOV. ~ Available in 5V, 8.5V and 10V (+ 4%) versions, these regulators also include reverse polarity pro- ORDERING NUMBER: wae CN, yy) tection, overvoltage protection, output current L4710CV (10V) limiting and a thermal shutdown circuit. ABSOLUTE MAXIMUM RATINGS Vv, Forward input voltage 35 Vv V, Reverse input voltage -18 Vv VE Positive transient peak voltage (t = 300 ms) +80 Vv Vt Negative transient peak voltage (t = 100 ms) -80 Vv Top Operating junction temperature -40 to 150 °c Tstg Storage temperature -55 to 150 °c BLOCK DIAGRAM | . — ; | PROTECT. { 1 | —[& RON 3¢ 33 5. sa960 a 143 4/87 ee
CONNECTION DIAGRAM (top view) 2 ouput © 3 (==> crouno CS incur Liap woanecieg Topr3 s-s893 TEST AND APPLICATION CIRCUIT The output capacitor is required for stability. Though the 47uF shown is the minimum recommended value, actual size and type may vary depending upon the application load and temperature range. Capacitor effective series resistance (ESR) also factors in the IC stability. Since ESR varies from one . brand to the next, some bench work may be required to determine the O a L4700 2 O minimum capacitor value to use in production. Worst-case is usually deter- Vv v mined at the minimum ambient temperature and maximum load expected. ' 3 — Output capacitors can be increased in size to any desired value above the OA uF minimum. One possible purpose of this would be to maintain the output voltages during brief conditions of negative input transients that might . A be characteristic of a particular system. 8-539
5 Capacitors must also be rated at all ambient temperature expected in the
system, Many aluminum type electrolytics will freeze at temperatures less than -30°C, reducing their effective capacitance to zero. To maintain regu- lator stability down to 40°C, capacitors rated at that temperature (such as tantalums) must be used. THERMAL DATA Ren j-case Thermal resistance junction-case max 4 °C/W eee 144
ELECTRICAL CHARACTERISTICS (v, = 14.4v, T, = 25°C) ee ee ee few [ee oe To [es | |e |v | AVo Temperature output mV AT+Vo voltage drift "CV SVR Supply voltage rejection 1g = 350 mA f= 120 Hz Cg = 100 uF ViRVot3V+2Vpp lee Output short circuit current 800 mA (*) Fora DC input voltage 28V < V; < 35V the device is not operating. output current a: so8s output current genes temperature geno: Ye 's TOOT “ PoC rm) . wET TT TT TTT TI (ie oo COC COCCeC eee Co a COLLET wo soe COCO eer Rocce) roel CoCo s eooeeoo rt T os COCO Eoeeeeoe CoOL LLL COC a s oboe ai nee FEE EEE FRR eA coo Clit oat EERE eeecereeeer ee Coe eT so OLCOTT et ECCCeeeeee 02 ran Coo Coeceeeee CoCo et CeCe riety yi COCO ees oo Coe et 1 TTPreee*e ete Coleen Cooper I ° erri rrr rr rrr rrr rrr Cerrrr rere rr 90-200 300600 gima) ° woe 200300400 yma) “40-20 0 20 460 60 80 100 fF, ("C) a 145